It seems to me that STEM could be on DSP 7 "alone", because it is the device that has the most important number of connections and so may need to be on a dsp with the most number of connection, to provide an overhead for more stuff... and place the channels and MB7 elsewhere. This could leave room in dsp 7 for other stuff.
Here you want to do a 40 channel mixer right (or 64? 64 seems a huge number for xite... it is in fact equivalent to 128 mono channels... ) the two stems should NOT be on the same dsp: better put the 247 on the biggest dsp, and the 167 on another one.
I am not sure it is a good idea to place all the mixer on the same DSP, it has the same effect as if it was an integrated mixer on 1 dsp... little chance that it works and it causes dsp messages quickly.
I think the best is to seperate stems from other modules (in terms of which dsp they are loaded on), or even, seperate stems from each other, to get a better balance of the load of the mixer on the various dsps.
Here on Scope, I have this DSP overload too due to roo many connections: it happens if i add 2 mb7 in the picture below. Then, I cannot connect everything together, and i will overload the dsp before I can do the connections. I don't think it is reasonable to go over 48 stereo channels (remember, it's like a 96 mono inputs mixer already) I mean you can load the devices, but then a few channels will refuse to connect.
That's where the DSP management of stem bus is useful: deactivating a few of them should free enough resources to finish connecting all routings on the same DSP slot.
I don't know about ASIO, but i think it takes ressources too, in scope i feel a difference so i have to limit myself to 16 stereo asio (32 outs). more than that, the system doesn't follow (but i am on a scope pro of 1998 so.... it is less performant than the models that ere released later).
I liked better your pics of projects that do work though
About SLI:
By the way, "don't sli" the Stems with MB7. You can SLI only components that are "parallel" : for ex: two stems togethers, channels together, MB7 together (with other MB)
You cannot SLI Link a stem with a channel, because it will switch both devices on "solo mode", resulting in a big mute of all channels most of the time.
It is only RS that can be connected to any device of the network without problem. But SLI is diferent.
It is not very easy to explain anyway and requires examples of "dos and donts".
That's how it should be done (48 stereo channels in scope, drawings by vincent van gogh, not me)
